Electric-arc lamp.



L. Ml MCBRDE.

v ELECTRIC ARG LAMP. APPMGATION FILED 0013.111, 1909.

Patented s911124, 1912.

2 SHEETS-SHEET 1.

L. M. MOBEIDE.

ELECTRIC AR LAMP.

APPLIGATION FILED 0017.18, 1909,

Patented sep1;.24,1912.

2 SHEETS-SHEET 2.

CIK

nrirrnn sra FATENT UFFICE.,

LEVJES M. MUBRDE, OF DENVER, CGL'JRADG, ASSGNOR- T0 TEE McBEIllE-FRAZIEBUAEC LAM? CQMPANY, F EENVE3, CGLORADO, A. ORPOEATN GF CQLORAD,

ELETRIC-AR-C LAMY?.

Specification of etters Patent.

Patente d Sept. 24, i912.

.To all whom t may concern:

Be it known that l, Lnvvrs M. MoBniDn, a citizen ol the United States of America, residing in the city and county of Denver and State oir' Colorado, have invented a new and useful Elect icurc Lamp, ot' which the following is a specication.

rl`his invention relates to improvements in electric arc lamps, and particularly to a style ot lamp adapted to be used in connection with headlights, stereopticons, moving picture machines and search-lights.

The object ot the invention isi lirst, to provide a lamp in which the usual flickering oli the light, due lo tlie feeding oi the electrodes, is preventedl second., to provide a lamp in which the arc is maintained in a predetermined fixed position, such as the focal point of a reflector used in conjunction with said lamp; and, third, to provide in connection Awith said lamp means tor controlling and directing the along the axis toward the vertex of the said reflector. These objects are accomplished by the mechanism illustrated in the accompanying drauf'- ings. in which:

Figure l is a view in elevation of the improved lamp arranged in connection With parabolic reflector, the rear end of which is (fut otl on the line l-l ot Fig. Q, :for clearer illustration. Fig. 2 is a central, vertical, longitudinal, sectional vieuT through the lamp. reflector and supporting bracket theretor. Fig. El is a front view showing the lamp used in connection with an ordinary headlightcasing, provided with a housing for receiving the upper ends of the electrode tubes and parts of the lamp mechanism. Fig, l is a plan view of Fig. 3, showing more clearly the hinged doors, which normally cover the openings through which the electrodes are passed into the holding tubes. Fig. 5 is a plan view or" a portion of the lanlp-supporting bracket; and Fig. G is a diagrammatic view illustrating the lamp circuit. l

Referring to the accompanying drawings: The numeral l indicates a headlight casing having the usual lass-front door Z hinged thereto. 1Within tie casing is placed a reflector 3, whichy is secured upon e bracket 4, which is adapted to be slid into the end of the casing. As illustrated in Fig. 2, the bracket- 4.-. comprises a horizontal base por- .oo nich is adapted to rest in guides secured, as will novv be described.

The platform 7 is provided at opposite ends with elongated apertures 8, and at the outside ends of the apertures are secured supports A and l respectively, each of which consists of a plate 9, having parallel ears l0, which lie on opposite 'sides of the aperture S, and bet-Ween cach pair of ears is pivotallysecured, in any suitable manner, an electrode holding and feeding tube il, which tubes extend through apertures l2, in the reflector and converge to a point on a line ivith the vertex of the said retlector. The plates 9 are insulated from the plat form '7.

The feed tubes ll entend a suitable distance above their supports, and the upper port-i ons enter a housing 13, which is formed on the top of the casing l. The top oi the housing is formed with openings 14,-, in line 7ith the adjacentends ol' the tubes, through which the electrodes lo are passed into the said tubes, and these openings are normally closed by hinged lids 16. The tubes are provided with stops 17, at their lower ends, which consist of pieces ot a highly refractory substance, preferably carborundum, which lit in holders 18 formed on the end or the tubes. These holders are arranged at e slight angle to the tubes, so that their axes intersect the axes o' the tubes a slight distance belowv the ends of the saine; thus, when the stops l? are inserted inthe holders, as clearly shown in 'Fifa l, they extend across the paths 'of the electrodes, which extend a slight distance beyond the lower ends of the tubes, and prevent their downward movernent beyond a predetermined'point.

Upon the platform 7, centrally between the tube supporters, is secured a solenoid 19 of the usual type, and in the lower end of the axial opening therein is secured an iron pole 20, which extends down through the reflector. The portion of the pole 20 lying Within the reflector is flattened to form a blade which lies between the electrode tubes and extends to Within a short distance .of their point of convergence. This pole forms a blow net for a purpose to be presently explained, and by flattening same it not onlv i rented extended to within a slight distance of they converging point of .the tubes, as above stated.

An iron plunger 2l extends into the upper end of the solenoid and terminates a suitable distance from the upper end of the pole 20. The opposite end of the armature is secured in the'bottoin of a movable dashpot cylinder 22, within which a piston 23 is supported upon an adjustable` threaded rod 24, which extends loosely through an aperture 'in the horizontal. arm 25 of an upright bracket 26, which 1s' secured at its lower end upon the top of the solenoid. A thumb nut 27 isv threaded to the upper end of the rod 24C and bears upon the arm 25, and by turning the said nut the rod and the piston 23 are adjusted vertically relatively to the dash pot. il, cross bar '28 is secured upon the upper portion of the rod 24 by nuts 29,

. and this bar is connected byV a pair of helical springs' 29A, with ears 30, which project from opposite sides of the dash "pot, and these springs normally hold the dash pot in a predetermined' position relatively to itspiston. i

A. cross head 3l of non-conducting material, preferably fiber, is suitably secured upon the armature 21, between the dash pot k and the solenoid, and a pair of toggle arms 32 are pivotally secured at their lower ends to opposite sides of this block, adjacent to its ends, and the upper ends of thevarms ar pivotally secured Abetween ears 33, which forni the terminal ends of bands 34, which are secured upon the electrode tubes; thus when the plunger descends in the solenoid vthe toggle arms draw upon the feed tubes, which are rocked on their pivots to separate the lower ends of the electrodes. The feed tube supports l and B are provided with binding screws and 36 respectively, and

a wire 37 connects the ,screw 35 with one end of the solenoid winding, while a wire 38 entends from the screw 36 of the sup-v port B to a battery 39, or other source ofl A wire 40 entends from the oppof ing is drawn into the solenoid and the cross head 31 is thereby moved downward, drawing upon the toggle arms 32, which rock the feed tubes on their pivots, and separate the lower ends of the electrodes, thus forming an arc, tho space between the' ends of the' electrodes being determined' by the @spies e this patent may be obtained for ve cents each, by

Losa-lea amount of resistance oered by the springs 29A to the action of the solenoid.

lt is a well known principle in magnetic phenomena that a magnetic Hun will produce a pressureon an arc, in general proportional to the strength of arc, dun, and relative directions of the two. The solenoid is so wired and its axis so positioned, that,'for a given direction of current in the arc, and hence in the solenoid, since its windings are in series with the carbons, the magnetic flux direction will be such as to exert a pressure upon the. arc and approximately at right angles t'o it, and in such direction as to push the arc to the lower ertremity of the carbons When the current direction. in the arc is reversed, of necessity,

the current in the coil is likewiseA reversed, and hence the polarity of the magnetic field is reversed. Thus the. direction of the side f thrust of the flux ony the arc is constant, keeping the are in one position, viz., the

lower extremity of the carbone. Under theinfluence of the magnetic flux of the blow magnet 20 the arc is maintained more nearly in the focal axis of thareflector, and this in conjunction with the uniform fee-ding of the electrodes not only eliminates flickering but prevents the arc from burning out of focus, thus giving much clearer and steadier vlight than would be possible when these conditions are lacking. p

The feed tubes are preferably made of brass or copper, and are nickel-plated in order to diffuse the light and prevent shadows.

The dash pot prevents sudden movement of the armature, due to the act-ion of the current in the solenoid.

llaving described rny invention, what l claim as new and desire to secure by lietters Patent is: v

An electric arc-lamp vhaving an electrode actuating solenoid, a plunger in said solo noid, a cylinder secured to the upper end of said plunger, a piston within said cyl-` inder, a threaded rod secured to said piston, a support forv said threaded rod, a cross-bar adjustably secured onsaid threaded rod havingsprings attached to its outer ends, and bands encircling the cylinder having projecting ears secured to the other ends of said springs, thereby providing means for keeping said cylinder normally in a iixed position.

ln testimony whereof I affix my signature in presence of two witnesses.

Lewis M. Messine? Witnesses G. Serenna? ELLIOTT, Anette M. Fownn.

addressing the Commissioner of Patents,

Washington, ID. Cj? 

